Europe’s best-performing blue-chip stock in 2025 is widely expected to be bought by a larger peer, in a deal analysts say could be worth as much as $23 billion.
Abivax, the French clinical-stage biotech company developing a treatment for ulcerative colitis and Crohn’s disease, saw shares rocket 1,681% last year, far outpacing the Stoxx 600 index’s second-best performing stock, mining company Fresnillo, which rose 453%.
Now, the big question for analysts seems to be when, not if, Abivax announces a deal.
The stock, listed in 2015, largely ranged between 10 and 20 euros but it wasn’t until 10 years later that it really took off. Shares surged 510% in a day after Abivax reported the results of a late-stage trial for an ulcerative colitis medicine in July, beating even the most optimistic expectations. After these kinds of results, it could be a strategic acquisition for any large pharmaceutical company with an immunology and inflammation franchise.
Abivax’s lead – and only – asset, obefazimod, was first developed as a treatment for HIV, but researchers discovered that its anti-inflammatory effect could affect other conditions like inflammatory bowel disease (IBD) and began clinical trials.
Shares were boosted even more in December as rumors emerged that the world’s most valuable pharma company, Eli Lilly, had its eyes set on acquiring Abivax. Both companies have repeatedly declined to comment on business development activities.
An imminent deal?
Analysts say that a deal could happen any time now.
Van Lanschot Kempen analyst Sebastiaan van der Schoot told CNBC that biotechs often “have a relatively small number of employees and don’t have any experience with selling a drug,” which he called “a completely different ball game” to developing them.
“That’s why pharma takes them out to actually leverage their infrastructure,” he said.
The analyst added that he expected Abivax to trade between where it is now and where it was when rumors of a takeover first surfaced, until the annual JP Morgan Healthcare Conference on Monday, where companies often announce large deals.
Abivax shares surged in 2025, far outpacing European peers.
It comes as Big Pharma has ramped up dealmaking in recent months, as the sector faces a looming patent cliff where some of the world’s best-selling drugs lose exclusivity in the coming years.
Another factor making a deal likelier is Abivax CEO Marc de Garidel’s reputation as a leader who can make deals happen. He previously led multi-billion dollar buyouts of biotech firms to pharma players like AstraZeneca and Novo Nordisk.
Asked about a potential acquisition, de Garidel told CNBC’s “Europe Early Edition” in December that the company was always in “conversation with Big Pharma” but that its role was to develop the best possible drug.
Abivax is planning to file for regulatory approval in the U.S. by the end of 2026, eyeing a potential launch by the third quarter of 2027, de Garidel said.
The company is well-positioned to negotiate a favorable deal with a Big Pharma partner, Stifel analyst Damien Choplain said.
“Given the strength of the Phase III results and the scarcity of comparable assets, we believe a transaction could be executed ahead of the maintenance data readout expected in Q2 2026,” he said, referring to a second clinical trial of Obefazimod which tests its efficacy over 44 weeks as opposed to only eight weeks.
Choplain added that most transactions in the IBD space have historically happened for drug candidates in earlier stages of development. “Abivax ticks all the boxes for a strategic acquisition,” he said.
Based on comparable transactions and a peak sales estimate of 3 billion euros, Abivax’s valuation could range between 12 billion euros and 20 billion euros ($14 billion to $23 billion), Choplain told CNBC.
Recent deals in the IBD space include Merck’s acquisition of Prometheus for $10.8 billion; Roche’s acquisition of Telavant for $7.1 billion; and Eli Lilly buying Morphic for $3.2 billion. Those deals were all for assets in an earlier stage of development than Abivax’s obefazimod.
A potential best-in-class treatment
Jefferies analyst Roger Song, who doesn’t cover Abivax per se but tracks the IBD space closely from Boston, said that investors’ optimism comes both from a multi-billion dollar potential market for IBD treatments, as well as from the drug candidate’s novel way of addressing it through multiple pathways.
It is even considered to be a potential best-in-class treatment for ulcerative colitis, he told CNBC in December.
The July results from the trial of Obefazimod surprised investors because many had not been aware of the novel mechanism it uses, micro-RNA, Song said.
A late-stage maintenance trial is expected in the second quarter of 2026.
Van der Schoot added that, if Abivax is confident enough in those maintenance results, it can wait to be acquired after the trial is published, “because then they can ask a higher price.”
